<template>
  <div class="cart">
    <h4>全部商品</h4>
    <!-- cart-main:购物车主体部分 -->
    <div class="cart-main">
      <!-- 头部标题 -->
      <div class="cart-th">
        <div class="cart-th1">全部</div>
        <div class="cart-th2">商品</div>
        <div class="cart-th3">单价（元）</div>
        <div class="cart-th4">数量</div>
        <div class="cart-th5">小计（元）</div>
        <div class="cart-th6">操作</div>
      </div>
      <!-- 购物车身体部分 -->
      <div class="cart-body">
         <!--ul代表一个商品-->
        <ul class="cart-list" v-for="(good,index) in cartInfoList" :key="good.id">
          <li class="cart-list-con1">
            <input type="checkbox" name="chk_list" :checked="good.isChecked==1"  @change="updateChecked(good, $event)"/>
          </li>
          <li class="cart-list-con2">
            <img :src="good.imgUrl">
            <div class="item-msg">{{good.skuName}}</div>
          </li>
          <li class="cart-list-con4">
            <span class="price">{{good.cartPrice}}</span>
          </li>
          <li class="cart-list-con5">
            <a href="javascript:void(0)" class="mins" @click="minus(good)">-</a>
            <input autocomplete="off" type="text" :value="good.skuNum" minnum="1" class="itxt" @input="changeshuNum(good, $event)">
            <a href="javascript:void(0)" class="plus" @click="add(good)">+</a>
          </li>
          <li class="cart-list-con6">
            <span class="sum">{{good.cartPrice * good.skuNum}}</span>
          </li>
          <li class="cart-list-con7">
            <a href="#none" class="sindelet" @click="removeGood(good)">删除</a>
            <br />
            <a href="#none">移到收藏</a>
          </li>
        </ul>
      </div>
    </div>
    <div class="cart-tool">
      <div class="select-all">
        <input class="chooseAll" type="checkbox" :checked="isChecked && cartInfoList.length>0 " @change="updateAllGoodChecked" />
        <span>全选</span>
      </div>
      <div class="option">
        <a @click="removeAllCheckedGood">删除选中的商品</a>
        <a href="#none">移到我的关注</a>
        <a href="#none">清除下柜商品</a>
      </div>
      <div class="money-box">
        <div class="chosed">已选择
          <span>{{ totalNum }}</span>件商品</div>
        <div class="sumprice">
          <em>总价（不含运费） ：</em>
          <i class="summoney">{{ totalPrice }}</i>
        </div>
        <div class="sumbtn">
          <router-link class="sum-btn" to="/trade">结算</router-link>
        </div>
      </div>
    </div>
  </div>
</template>

<script>
import { mapGetters } from 'vuex';
// 通过辅助函数mapGetters 获取用户购物车的数据
import throttle from "lodash/throttle";
// 防抖
import debounce from "lodash/debounce";
  export default {
    name: 'ShopCart',
    //组件挂载完毕，获取一次购物车数据
    mounted() {
      // 获取一次用户购物车数据
      this.getData();
    },
    computed: {
    ...mapGetters(["cartInfoList"]),
    //商品总个数
    totalNum() {
      //利用reduce计算用户购买商品的总个数----for循环也可以
      let totalNum = this.cartInfoList.reduce((pre, next) => {
        //三次执行: 第一次 pre 0   next: 1   结果1
        //         第二次 pre 1    next:2   结果3
        //         第三次 pre 3    next:16  结果19
        return pre + next.skuNum;
      }, 0);
      return totalNum;
    },
    //总价
    totalPrice() {
      return this.cartInfoList.reduce(
        (pre, next) => pre + next.skuNum * next.cartPrice,
        0
      );
    },
     //全选√不勾判断
     isChecked(){
      return this.cartInfoList.every(good=>good.isChecked===1);
      //先把商品已经勾选的过滤出来
      // let arr = this.cartInfoList.filter(item=>{
      //     return item.isChecked ==1;
      // });
      // return arr.length===this.cartInfoList.length?true:false;
    }
  },
  methods: {
    //获取用户购物车数据的方法
    getData() {
      this.$store.dispatch("getUserCartList");
    },
    //商品数量加号回调
    async add(good) {
      let skuId = good.skuId;
      let skuNum = 1;
      //通知vuex发请求修改商品数量
      try {
        //修改商品成功以后
        await this.$store.dispatch("updateGoodSkuNum", { skuId, skuNum });
        //再次获取购物车修改以后数据
        this.getData();
      } catch (error) {
        //弹出提示信息
        alert(error.message);
      }
    },
    //商品数量减号回调
    minus: throttle(async function (good) {
      //商品的数量修改确实可以，保证商品数量个数大于1
      if (good.skuNum > 1) {
        let skuId = good.skuId;
        let skuNum = -1;
        //派发请求修改商品数量
        //通知vuex发请求修改商品数量
        try {
          //修改商品成功以后
          await this.$store.dispatch("updateGoodSkuNum", { skuId, skuNum });
          //再次获取购物车修改以后数据
          this.getData();
        } catch (error) {
          //弹出提示信息
          alert(error.message);
        }
      }
    }, 1000),
    //商品中间文本框的回调
    changeSkuNum: debounce(async function (good,event) {
      //如果用户输入内容非法:修改变化数值0，这个数值不能变
      //如果用户输入内容正常:16->21,变化后的数值 5    16->8,变化后的数值-8
      let userValue = event.target.value * 1;
      //携带参数
      let skuId = good.skuId;
      let skuNum = 0;
      if (isNaN(userValue) || userValue < 1) {
        //指定非法
        skuNum = 0;
      } else {
        //合法的携带变化数值:用户输入完的结果数值减去起始数值
        skuNum = Math.ceil(userValue) - good.skuNum;
      }
      //整理完毕参数再次发请求
      try {
        //修改商品成功以后
        await this.$store.dispatch("updateGoodSkuNum", { skuId, skuNum });
        //再次获取购物车修改以后数据
        this.getData();
      } catch (error) {
        //弹出提示信息
        alert(error.message);
      }
    }, 1000),


     //修改某一个商品勾选状态
     async updateChecked(good, e) {
      //商品ID
      let skuId = good.skuId;
      //勾选状态
      let isChecked = e.target.checked ? "1" : "0";
      try {
        //派发action通知vuex发请求，让服务器修改商品的勾选状态
        //修改商品状态成功以后
        await this.$store.dispatch("updateGoodChecked", { skuId, isChecked });
        //再次获取购物车最新的数据
        this.getData();
      } catch (error) {
        alert(error.message);
      }
    },
    //删除某一个商品
    async removeGood(good){
      try {
        //删除商品成功
       await this.$store.dispatch('removeGoodById',good.skuId);
       //再次获取购物车最新的数据
       this.getData();
      } catch (error) {
        alert(error.message);
      }
    },

    //删除用户选中的全部商品
    //没有一次删除多个商品的接口，只有一次删一个！！！
    //需要保证:勾选商品有五个,这个五个都删除务必，在获取最新的购物车数据
    async removeAllCheckedGood() {
      //派发action通知vuex发请求
      try {
        //代表全部的勾选商品都删除成功以后
        await this.$store.dispatch("removeAllCheckedGood");
        //在获取购物车数据
        this.getData();
      } catch (error) {
        alert(error.message);
      }
    },

     //全选复选框的回调
     async updateAllGoodChecked(e){
       //获取全选复选框勾选状态数值
       let isChecked = e.target.checked?'1':'0';
       //派发action:当全部商品勾选状态修改完毕，再次获取购物车最新数据
      try {
        //保证全部商品勾选状态一次修改完毕
        await this.$store.dispatch('updateAllGoodChecked',isChecked);
        //再次获取购物车最新的数据
        this.getData();
      } catch (error) {
        alert(error.message);
      }
    },
  },
};
</script>

<style lang="less" scoped>
  .cart {
    width: 1200px;
    margin: 0 auto;

    h4 {
      margin: 9px 0;
      font-size: 14px;
      line-height: 21px;
    }

    .cart-main {
      .cart-th {
        background: #f5f5f5;
        border: 1px solid #ddd;
        padding: 10px;
        overflow: hidden;

        &>div {
          float: left;
        }

        .cart-th1 {
          width: 25%;

          input {
            vertical-align: middle;
          }

          span {
            vertical-align: middle;
          }
        }

        .cart-th2 {
          width: 25%;
        }

        .cart-th3,
        .cart-th4,
        .cart-th5,
        .cart-th6 {
          width: 12.5%;

        }
      }

      .cart-body {
        margin: 15px 0;
        border: 1px solid #ddd;

        .cart-list {
          padding: 10px;
          border-bottom: 1px solid #ddd;
          overflow: hidden;

          &>li {
            float: left;
          }

          .cart-list-con1 {
            width: 15%;
          }

          .cart-list-con2 {
            width: 35%;

            img {
              width: 82px;
              height: 82px;
              float: left;
            }

            .item-msg {
              float: left;
              width: 150px;
              margin: 0 10px;
              line-height: 18px;
            }
          }

          .cart-list-con3 {
            width: 20.8333%;

            .item-txt {
              text-align: center;
            }
          }

          .cart-list-con4 {
            width: 10%;

          }

          .cart-list-con5 {
            width: 17%;

            .mins {
              border: 1px solid #ddd;
              border-right: 0;
              float: left;
              color: #666;
              width: 6px;
              text-align: center;
              padding: 8px;
            }

            input {
              border: 1px solid #ddd;
              width: 40px;
              height: 33px;
              float: left;
              text-align: center;
              font-size: 14px;
            }

            .plus {
              border: 1px solid #ddd;
              border-left: 0;
              float: left;
              color: #666;
              width: 6px;
              text-align: center;
              padding: 8px;
            }
          }

          .cart-list-con6 {
            width: 10%;

            .sum {
              font-size: 16px;
            }
          }

          .cart-list-con7 {
            width: 13%;

            a {
              color: #666;
            }
          }
        }
      }
    }

    .cart-tool {
      overflow: hidden;
      border: 1px solid #ddd;

      .select-all {
        padding: 10px;
        overflow: hidden;
        float: left;

        span {
          vertical-align: middle;
        }

        input {
          vertical-align: middle;
        }
      }

      .option {
        padding: 10px;
        overflow: hidden;
        float: left;

        a {
          float: left;
          padding: 0 10px;
          color: #666;
        }
      }

      .money-box {
        float: right;

        .chosed {
          line-height: 26px;
          float: left;
          padding: 0 10px;
        }

        .sumprice {
          width: 200px;
          line-height: 22px;
          float: left;
          padding: 0 10px;

          .summoney {
            color: #c81623;
            font-size: 16px;
          }
        }

        .sumbtn {
          float: right;

          a {
            display: block;
            position: relative;
            width: 96px;
            height: 52px;
            line-height: 52px;
            color: #fff;
            text-align: center;
            font-size: 18px;
            font-family: "Microsoft YaHei";
            background: #e1251b;
            overflow: hidden;
          }
        }
      }
    }
  }
</style>